JPH05210752A - Optical fiber type bar code scanner - Google Patents

Abstract

PURPOSE:To obtain an optical fiber type bar code scanner capable of mounting a scanner head also in a small space restricted in an apparatus and having structure suppressing the influence of peripheral noise. CONSTITUTION:A module part 15 provided with a light emitting element 12, a driving circuit 13 and a detection circuit 14 is connected to a scanner head 11 including a lens and a light emitting element through a light receiving fiber 16 and a wire 17 to constitute the bar code scanner. Since the element 12 and respective circuits 13, 14 can be separated by using optical fibers, the scanner head 11 can be compacted and bar code scanning can be attained even in a restricted small space. Since the module part 15 can be set up in an environment reduced at its noise, the reliability of bar code detection can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention can be installed in a limited space, such as in equipment, for scanning bar codes,
It is possible to detect the bar code with high reliability and output it as an electric signal.

[0002]

2. Description of the Related Art A general bar code scanner is constructed by mounting a light emitting / receiving element, a drive circuit, a detection circuit and a lens system in a scanner head.

As the above-mentioned prior art, for example, the technology described in "All about bar code", page 67, page 68, page 76, etc., issued by the component division of Yokogawa Hewlett Packard Co., Ltd., is known. Has been.

FIG. 4 is a diagram showing the structure of a conventional scanner head. In FIG. 4, 23 is a light emitting element, 1
Reference numeral 2 is a light receiving element, 22 is a holder, and 25 is a convex lens.

In the conventional scanner head shown in FIG. 4, a light emitting element 23, a light receiving element 12 and a convex lens 25 are housed inside a holder, and further signals from a light emitting element drive circuit and a light receiving element (not shown) are received. The detection circuit is housed in the holder 22. In the conventional scanner, when the bar code is read, the light from the light emitting element 11 is condensed via the convex lens 25 on the surface of the paper on which the bar code (not shown) is printed, and its reflection is reflected. The light passes through the light receiving element 12 and is detected by a detection circuit (not shown).
The code is read.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since the scanner head contains a light emitting element, a light receiving element, a drive circuit, a detection circuit, and a lens system, the scanner head becomes large and it is difficult to mount it in a limited space when used in a device. There are many. In addition, there is a problem in that malfunctions are likely to occur due to noise from inside and around the device.

The object of the present invention is to solve the above-mentioned problems of the prior art and to mount the scanner head on a limited small space in the apparatus, and without being affected by ambient noise. Optical fiber bar that enables good reading
It is to provide a code scanner.

[0008]

According to the present invention, the above object is to separate a light receiving element, a drive circuit, and a detection circuit, which have a large mounting space, from the scanner head, and to optically connect these elements and the scanner head with an optical fiber. This is accomplished by combining the scanner head with a lens, a light emitting element that optically couples with the lens, and one or more fibers arranged concentrically around the lens.

[0009]

Since the light receiving element, the drive circuit, and the detection circuit, which have a large mounting space, are separated from the scanner head by the optical fiber, the scanner head can be downsized and can be mounted in a limited space in the device. Become. Further, since the light receiving element and the detection circuit, which are easily affected by noise, can be installed in a place where the noise is small and the environmental conditions are favorable, the malfunction can be reduced.

A lens provided at the tip of the scanner head can focus the light beam from the optical element on the bar code on the printing paper surface with a small spot. The collected emitted light beam is diffusely reflected on the surface of the bar code sheet and again enters the scanner head and is received by the light receiving fiber.

The present invention can provide a bar code scanner which can be housed in a small space and is not affected by noise as described above. Further, since the emitted light beam is a direct beam from the optical element through the lens, for example, the amount of light is insufficient due to the coupling loss that occurs when the light emitting element is separated from the scanner head by the optical fiber. Does not require high performance.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bar code scanner according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention,
2 is a sectional view showing the structure of the scanner head, and FIG. 3 is a view showing the structure of the optical fiber.

In one embodiment of the present invention, as shown in FIG. 1, a module unit 15 having a light receiving element 12, a drive circuit 13 and a detection circuit 14 and a scanner head 11 are connected by a light receiving fiber 16 and an electric wire 17. It is configured.

In one embodiment of the present invention configured as described above, the signal driven by the drive circuit 13 is
The electric wire 17 converts the light into light from a light emitting element (not shown). This light is collected by a lens (not shown), emitted from the scanner head 11, and projected onto the paper on which the bar code is printed. Scanner head or bar
The print surface of the code is moved and the reflected light from the print surface modulated by the bar code is incident on the scanner head 11 again, and is incident on the light receiving element 12 from the other end of the fiber via the light receiving fiber 16. Then, the detection circuit 14 outputs the pulse signal as a TTL level or the like according to the bar code.

Now, for example, a small space in a device is limited.
When the bar code is detected in the space, the light receiving element 12,
The module unit 15 including the drive circuit 13 and the detection circuit 14 can be mounted on a place with a space in terms of space apart from the scanner head. Further, by mounting the module unit 15 in a place with a good environment, it is possible to perform reliable bar code detection without being affected by noise or the like.

The structure of the scanner head 11 is shown in FIG.
Various configurations can be adopted as shown in FIG. That is, as shown in FIG. 2A, the ball lens 21 is provided at the tip of the head of the holder 22 so that the ball lens 21 and the light emitting element 23 are coupled at a constant distance d.
The distance d from 3 is optimally set so that the depth of focus can be deep.

2 (b) and 2 (c), the lens at the front end of the scanner head is replaced with a gradient index lens 24 and a convex lens 25, respectively, and the present invention thus detects the bar code. Various lenses can be used depending on the performance.

The structure of the light receiving fiber 16 is shown in FIG.
Various configurations can be adopted as shown in the sectional view of FIG.

In FIGS. 3A, 3B and 3C, the lenses 32, 34 and 36 are arranged at the center, and one or more light receiving fibers 31, 33 and 35 are concentrically arranged around them. It is arranged on the top.

Now, a light beam emitted from the light emitting element 23
The lens is narrowed down by the lenses 32, 34 and 36 to form a spot of a certain size on the printing paper surface. Then, the scattered reflection light from the surface of the printing paper is incident on the scanner head 11 again and can be received by the light receiving fibers 31, 33, and 35.

[0022]

As described above, according to the present invention, by using the optical fiber, the light receiving element, the driving circuit,
Since the detection circuit can be separated from the scanner head, the scanner head can be miniaturized and the bar code can be scanned with a limited small space. Further, since the light receiving element and the detection circuit which are susceptible to noise can be separated from the scanner head and provided in an environment with less noise, the reliability of bar code detection can be improved.

Further, according to the present invention, since the light beam from the light emitting element is directly condensed by the lens, for example, the light beam from the light emitting element is incident on the fiber, The light loss can be made very small as compared with the case where the end is combined with a lens to collect light. As a result, the detection circuit can be simply constructed and is not expensive.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a scanner head.

FIG. 3 is a diagram showing a configuration of a fiber.

FIG. 4 is a diagram showing a configuration of a scanner head according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Scanner head, 12 ... Light receiving element, 13 ... Drive circuit, 14 ... Detection circuit, 15 ... Module part, 1
6 ... Receiving fiber, 17 ... Electric wire, 21 ... Ball lens,
22 ... Holder, 23 ... Light emitting element, 24 ... Gradient distribution lens, 25 ... Convex lens, 31, 33, 35 ... Light receiving fiber, 32, 34, 36 ... Lens

Claims (3)

[Claims] 1. A bar code scanner comprising a light emitting element, a light receiving element, a drive circuit and a detection circuit, which outputs a bar code on a printing paper surface as an electric signal.
An optical fiber bar code scanner characterized in that one end of a fiber bundle constituted by at least two optical fibers is optically coupled and the other end is a head for scanning a printing paper surface. 2. The optical fiber type fiber reader according to claim 1, wherein the head for scanning the printing paper surface is constructed by incorporating a lens, a coupling portion between the lens and the light emitting element, and one end of a fiber bundle. -Code scanner. 3. The optical fiber according to claim 1, wherein the fiber bundle is composed of one or more light-receiving fibers arranged concentrically around a light emitting element or a lens. Type bar code scanner.